Mechanical Engineering - MCQ Practice Questions

A shaft is designed to transmit 50 kW at 1500 RPM. If the material has a yield strength of 400 MPa and a factor of safety of 2.5, what is the minimum shaft diameter required using the maximum shear stress theory?

Which of the following is the primary function of a flexible coupling in machine design?

In belt drive design, if the velocity ratio is 3:1 and the smaller pulley has a diameter of 100 mm, what should be the diameter of the larger pulley?

A cast iron flywheel has a mean diameter of 800 mm and rotates at 600 RPM. If the allowable tensile stress is 60 MPa, what is the maximum thickness of the rim?

Which type of key is most suitable for transmitting high torque in rotating shafts with frequent load reversals?

A riveted joint connecting two steel plates has 6 rivets arranged in two rows. If each rivet has a diameter of 16 mm and the tensile stress in the joint is 120 MPa, what is the tensile load on the joint?

In spur gear design, the module is 4 mm and the number of teeth on the pinion and gear are 20 and 60 respectively. What is the center distance between the gears?

A rolling contact bearing has an equivalent dynamic load of 8 kN and a rating life of 10,000 hours at 1500 RPM. Which bearing parameter is most affected by speed and load combination?

Which of the following statements is TRUE regarding stress concentration in machine design?

In a multi-plate clutch, if there are 5 pairs of friction surfaces and the coefficient of friction is 0.3, what is the relationship between the torque transmitted and the axial force?

A spring is subjected to a tensile stress of 600 MPa. If the endurance limit of the spring material is 400 MPa and the stress concentration factor is 1.8, what is the factor of safety against fatigue?

Which of the following materials is BEST suited for manufacturing hydraulic cylinder pistons?

In a worm gear drive with a single-start worm, module 2 mm, and 40 teeth on the gear, what is the worm pitch?

A deep groove ball bearing is subjected to a radial load of 5 kN and an axial load of 2 kN. If the X and Y factors for this bearing are 0.56 and 1.8 respectively, what is the equivalent dynamic load?

In brake design, which factor is MOST critical when designing brakes for automotive applications operating at high temperatures?

A hollow shaft has an outer diameter of 60 mm and inner diameter of 40 mm. What is the polar moment of inertia of the shaft?

In a power screw design, if the pitch is 5 mm, major diameter is 20 mm, and the coefficient of friction is 0.15, what is the efficiency of the screw?

Which type of bearing is preferred for applications requiring self-alignment capability?

A V-belt drive operates with a belt velocity of 20 m/s and transmits 30 kW. If the belt has a mass of 0.5 kg/m, what is the centrifugal tension in the belt?

In gear tooth bending stress analysis according to Lewis equation, which parameter does NOT directly affect the bending stress?